WESTWOOD (CBSLA.com) — Hundreds of cars were submerged by Tuesday’s massive water main break in Westwood.

An estimated 20 million gallons of water were lost when a high-pressure water main burst on Sunset Boulevard in front of Marymount High School on Tuesday, flooding two parking structures on the UCLA campus.

KCAL9’s Amy Johnson reports more than 900 cars, many belonging to students, staff and faculty, are stuck inside structures 7 and 4 on the north side of the campus. About half those are believed to be damaged.

“I ran outside and saw the river of water just flowing down into the parking lot,” said UCLA employee Courtney Miller, whose Volkswagen Passat is among vehicles in the structures.

“I’ve never seen anything like it before. There was so much water and dirt, and I just pictured my car totally floating away,” she said.

UCLA Chancellor Gene Block told CBS2/KCAL9 his priority is removing the water, which also caused severe damage to Drake Stadium, an intramural athletic field and the newly renovated Pauley Pavilion, as quickly as possible.

“There’s a lot of damage to our athletic facilities and to our garages. And this caused a lot of pain for our employees, our students and visitors, whose cars are stuck here,” Block said.

“I’m concerned about getting that water pumped out as quickly as we can.”

UCLA Assistant Vice Chancellor Kelly Schmader warned, however, the work will take time to complete.

“We’re currently removing about 4,000 gallons per minute. And we would like to do more but the problem is that we only have right now about 6,000 cubic feet per minute of exhaust. And the more pumps we bring online, the more issues we have with carbon monoxide,” Schmader said.

It remains unclear who will pay for the damage.

“We’ve asked them to contact their own insurance companies, but we’ll have to deal with that situation because this was caused by an event that was external to UCLA,” the school’s vice chancellor, Jack Powazek, said.

Crews expect to have the water out by Friday. The campus is not expected to open until then.

Vehicles are then expected to be towed and taken to a location where owners can claim them.